A model of rhythm generation and functional connectivity during a simple motor task: preliminary validation with real scalp EEG data

A simple original model of five interconnected neural populations is used to investigate the origin of EEG rhythms in the cerebral cortex during a simple motor task. The model considers three regions of interest (the cingulated cortex, the primary motor cortex and the supplementary motor cortex), each oscillating with a medium-frequency rhythm, and two additional remote regions (without a clear anatomical counterpart) able to induce alpha and gamma rhythms. The model has been fitted (in terms of power spectral density, PSD, and coherences among populations) to real EEG data measured on the scalp on a volunteer during a right foot movement task and then propagated to the cortex. The estimated parameters include the connectivity weights among the populations, and the time constants of intra-area excitatory synapses. Results show that the model is able to simulate the occurrence of multiple PSD peaks in the three examined regions quite well, at the same time providing realistic values of coherence. It can be useful to gain a deeper insight into the functional connectivity links occurring among brain regions during simple tasks, and provide artificial data for testing existing algorithms. Virtues and possible limitations of the method are discussed, and lines for future research pointed out.